As devices such as mobile phone, digital AV apparatuses, IC cards etc. have been improved to have higher performance, semiconductor silicon chips (hereinafter, refer to as chips) to be mounted on the devices have to be smaller and thinner in order to greatly increase a number of chips mounted in packages of the devices. To greatly increase a number of chips mounted in the package, the chips should have a thin thickness in a range of 25 to 150 μm.
However, semiconductor wafers (hereinafter, refer to as wafers) to be substrates of the chips is weakened in strength when the wafers are polished to a thin thickness. The thin wafers with weak strength are easy to be cracked or curved. Moreover, the thin wafers with weak strength are difficult to transport by automatic transportation. This requires manual transportation, and thereby tedious handling.
To deal with this problem, a wafer support system has been developed to reinforce the strength of the wafers by adhering a plate (called a supporting plate, and generally made from glass or rigid plastic) to the wafers before polishing. The wafer support system prevents cracking and curving of the wafer. The wafer support system, which reinforces the strength of the wafers, allows automatic transportation of the thin semiconductor wafers.
The wafers and supports are adhered with each other via an adhesive tape, thermoplastic resin, an adhesive, or the like. After a wafer adhered with the supporting plate is thinned, the wafer is stripped off from the supporting plate before dicing. For example, in case where the wafer and the supporting plate are adhered with each other via an adhesive, the adhesive is dissolved so as to strip the wafer off from the supporting plate.
Patent Literature 1 discloses one example of such a technique of stripping a support plate from a wafer. In the technique of Patent Literature 1, the dissolving an adhesive layer for adhering a wafer and a support plate having holes is carried out by soaking into a solvent the support plate having holes, so as to deliver the solvent to the adhesive layer via the holes. Patent literature 1 also discloses that the dissolving the adhesive agent adhering the wafer and the support plate is carried out by supplying the solvent onto a surface of the support plate and vibrating the solvent so as to facilitate the dissolving the adhesive agent with the solvent. Moreover, Patent Literature 2 discloses that a solvent is supplied onto a support plate having holes and the solvent is delivered to the adhesive layer via the holes.